1. Field of the Invention
The present invention relates to an image sensor, and more particularly, it relates to an image sensor including a photoelectric conversion film.
2. Description of the Background Art
A stacked image sensor formed by stacking a photoelectric conversion film on pixel electrodes is known in general. For example, known is a CCD image sensor chip (image sensor) comprising pixel electrodes, dummy electrodes formed adjacently to endmost pixel electrodes and a photoconductor film (photoelectric conversion film) arranged on the pixel electrodes and the dummy electrodes. In this CCD image sensor chip, a positive potential is applied to the dummy electrodes for pouring and ejecting charges generated from the photoconductor film outside the endmost pixel electrodes into the dummy electrodes thereby inhibiting the charges generated outside the endmost pixel electrodes from flowing into the endmost pixel electrodes. Thus, endmost pixels corresponding to the endmost pixel electrodes are inhibited from reaching excessively bright levels due to increased signal charges therein.
In the conventional CCD image sensor chip, however, the positive potential is so regularly applied to the dummy electrodes that parts of charges generated in the vicinity of the boundaries between the dummy electrodes and the endmost pixel electrodes to originally flow into the endmost pixel electrodes disadvantageously flow into the dummy electrodes. Therefore, the quantities of the signal charges in the endmost pixels corresponding to the endmost pixel electrodes are so reduced that the endmost pixels are recognized darker than the actual levels. Thus, it is difficult to correctly control the signal charges flowing into the endmost pixel electrodes in the conventional CCD image sensor chip.